+ (if (listp group-by)
+ (do ((order group-by (cdr order)))
+ ((null order))
+ (let ((item (car order)))
+ (typecase item
+ (cons
+ (output-sql (car item) database)
+ (format *sql-stream* " ~A" (cadr item)))
+ (t
+ (output-sql item database)))
+ (when (cdr order)
+ (write-char #\, *sql-stream*))))
+ (output-sql group-by database)))